Mind over matter? The ethics of using the placebo effect

Author

Professor of Neurophysiology, Department of Physiology, Flinders University

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Marcello Costa does not work for, consult to, own shares in or receive funding from any company or organisation that would benefit from this article, and has no relevant affiliations.
Marcello as member of the Australian Academy of Science, is committed to support the highest scientific standard in education and tertiary institutions.
Flinders University is a Member of The Conversation.

There’s good evidence showing expectations to get better have significant effects on how patients suffering a variety of ailments feel. This is called the placebo effect from the original meaning in Latin, I will please.

The placebo effect is a perceived or actual improvement of a medical condition that occurs even when the people are given inert treatments – the proverbial “sugar pill”. It reflects the ability of the brain to control many states of the body, even those not under voluntary control.

One well-documented example of the placebo effect explained by the activation of brain pain suppressant mechanisms – endorphins – was shown 30 years ago. Patients with dental pain after an operation were given either naloxone, a drug that prevents the actions of endorphins, or a placebo.

The placebo pain relief was due to the release of endorphins, indicating that the improvement in the subjective feeling of pain is similar to that experienced with actual painkillers. Numerous other studies since have revealed many self-healing responses based on the placebo effect.

Nocebo effect

The brain can also influence health in a harmful way. This is the nocebo effect (from Latin nocere meaning to harm). Well-documented examples of nocebo effect are the adverse effects some life stresses have on the heart. Substantial scientific evidence links coronary heart disease and depression, social isolation and lack of social support. It seems heartache and social rejection can indeed kill you.

Research on both placebo and nocebo effects is in its infancy and reveals that the ability of the brain to influence some diseases depends on high neural centers. Diseases lacking major influences from these centers are less prone to improvement by placebos.

Pain is significantly affected by higher brain centers, so it’s open to the placebo effect and also to a significant nocebo effect – transforming a mild pain in a severe one. Tumours are little influenced, if at all, by the brain, so they’re not really improved by the placebo effect, although the patients may feel subjectively better.

Ethics of placebo

We know that the placebo effect may improve some ailments. We also know that in many cases the placebo effect change how people feel about the disease, improving the quality of life. But is its use ethical? If placebo treatments can be effective in treating some conditions by the “self-healing” capabilities of the brain, is it ethical to use costly medical interventions instead?

These questions have risen in clinical sciences since World War II, as a result of the widespread adoption of randomised controlled trial in scientific medicine. It was noticed then that people in placebo control groups improve, sometimes dramatically.

Since then, clinical trials in most western countries have been required to take the placebo effect into account. This requirement was introduced in a revision of the Declaration of Helsinki (first drawn up in 1964) issued by the World Medical Association in October 2000.

In a 2002 paper in The Lancet, researchers concluded that provided “the safety and interests of individual patients are carefully protected, the conduct of placebo-controlled trials in these situations remains vital if correct regulatory decisions are to be made on the basis of reliable research.”

So clinicians, researchers and pharmaceutical companies are engaged in a search for ethical and effective treatments while taking the placebo effect into account. There’s clear consensus that deception in treatments is unacceptable in modern medical practice.

But many of the mild improvements in current general practice medicine are probably due to the placebo effect; the most frequently prescribed placebos by general practitioners are antibiotics for viral infections, and vitamins for fatigue.

It appears that modern alternative and complementary medicines (CAM) also work mostly by the placebo effect. Most randomized placebo controlled trials on the efficacy of some of the most commonly used alternative medicines demonstrate that they are no more effective than placebo treatments.

One of the best early examples of scientific testing on the validity of a doubtful treatment was the testing of the existence of an alleged mysterious psychic force, called animal magnetism. This mysterious force linking all animated and inanimate objects, was proposed by Anton Mesmer (hence the term mesmerize), a German physician with an interest in astronomy. It was used to treat patients suffering various ailments.

Because some patients actually improved during the mesmerizing procedure, the then-king of France had a group of scientists and physicians test the existence of this mysterious fluid. The commission concluded that there was no evidence for it, and whatever benefit the treatment produced was attributed to “imagination”.

The power of imagination and self-suggestion have been documented in most cultures for thousand of years, with the use of witchcraft and sorcery. Both claim to use supernatural or magical powers, such magic spells, curses or magic potions, to influence people either favorably or adversely. Such potions and spells work almost certainly as placebo and nocebo effects, and were based fundamentally on deceptions on gullible people.

In this sense, alternative and complementary medicines represent the modern version of witchcraft and sorcery. They too claim mysterious explanations for their remedies and deception is still the norm in these non-regulated, non-medical industries. This raises very significant ethical issues about their legitimacy in a modern, well-regulated, health public system.

The scientific study of the placebo and nocebo effect is part of the exciting advances in modern neuroscience on the way in which the brain normally controls many bodily functions. We do know that this is mostly done by operating below conscious awareness.